Encopresis & MIE (DoD #2)

Brief description of study

This study is comparing 2-week and 1-week versions of a multidisciplinary intervention for
encopresis (MIE), consisting of both medical and behavioral components to treatment as usual
control (TAU). Participants are first screened by a pediatric gastroenterologist and assessed
and treated for any constipation or other potential medical complications. Following this,
caregivers collect data on bowel movements and continence during a home baseline lasting no
less than 14 days and no more than 21 days. Participants randomly assigned to one of the
treatment groups start attending daily appointments in clinic for either 1 week or 2 weeks.
At appointments, the behavior team implements structured sits on the toilet to promote
independent bowel movements (BMs). If an independent BM does not occur, the study team will
administer a suppository to promote rapid release of the bowels and prompt the child to
remain on the toilet following administration. In doing so, continent bowel movements are
predictably evoked while the child is on the toilet, allowing for reinforcement with praise
and preferred toys/activities. Eventually, suppositories are gradually decreased until the
child is having BMs independently. Caregivers are trained to continue implementing the
intervention following the clinic-based portion.

The purpose of the current study is to evaluate MIE using a large randomized clinical trial
(RCT), addressing the Department of Defense Autism Research Program, Area of Interest of
Therapies to Alleviate Conditions Co-Occurring with autism spectrum disorder (ASD). The
researchers will recruit 150 children diagnosed with ASD, randomizing them to 2 weeks of MIE
, 1 week of MIE, or treatment as usual (TAU) consisting of behavioral consultation and
medical intervention. This study will evaluate MIE compared to TAU and determine the optimal
treatment length.

Detailed Study Description

Toilet training one's child is a nearly universal challenge for parents, but is a
particularly distressing ordeal for parents of individuals with autism spectrum disorder
(ASD). Whereas typically developing children generally stop having daytime toileting
accidents (i.e., they achieve continence) by 2-4 years of age, most individuals with ASD are
either delayed in their acquisition of toileting skills, or never achieve continence.
Furthermore, toileting concerns are a significant contributor to the increased stress
experienced by caregivers of those with ASD. Besides dramatically increasing their burden of
care, not being fully toilet trained negatively impacts the individual with ASD's hygiene,
self-confidence, physical comfort, and independence while also causing social stigma.
Incontinence can also have serious collateral consequences, such as limiting exposure to
important life experiences. Furthermore, without effective treatment these problems generally
persist into adulthood.

One reason why strictly behavioral treatments of encopresis have shown only limited success
may be due to the fact that it often has a medical etiology. Encopresis is when underwear are
soiled by stool in children over the age of toilet training and long-standing constipation is
the cause of encopresis in the majority of children who exhibit it. Children with ASD are
more likely to have constipation than typically developing children. Constipation causes
encopresis by creating a cycle of withholding bowel movements (withholding is the voluntary
contraction of the external sphincter to avoid a bowel movement): constipation causes painful
bowel movements, which triggers further withholding behavior, exacerbating constipation. Over
time the colon adapts by dilating, which leads to larger fecal masses in the rectum. Thus,
the passage of larger and harder (i.e., painful) stools further increases an individual's
withholding behavior. Over time, the rectum and colon become so dilated that the individual
loses sensation. With no urge to defecate, an individual is even more likely to have stool
accumulate in the rectum and is also unable to control bowel movements. Looser stool may leak
around hard stool leading to an unintended leakage and sometimes large evacuation of stool
occurs without the individual realizing it.

Although purely medical approaches can successfully treat constipation in individuals with
ASD, they have not shown long term success with encopresis. That is, medical approaches can
treat a single episode of constipation, but without acquiring toileting skills, the
individual is likely to become constipated again, repeating the cycle. Conversely, purely
behavioral strategies have not been shown to be effective at treating encopresis in
individuals with ASD, even when they are not experiencing constipation. One reason for this
lack of success may have to do with the fact that it is often difficult to predict the timing
of a bowel movement so that caregivers can ensure the individual is sitting on the toilet
when one takes place and then reinforce continence. Thus, a multidisciplinary approach
incorporating both medical and behavioral approaches is necessary in the treatment of
encopresis in individuals with ASD.

This is an 8-week, randomized clinical trial of 150 children, ages 5 to 12 years, 11 months
with ASD and encopresis. Subjects will be randomized in a 2:2:1 ratio to receive either one
week of MIE, two weeks of MIE or one week of TAU.